* Crankshaft Position Sensor (CKP): This sensor tells the computer the position of the crankshaft, crucial for proper ignition timing. A faulty CKP sensor will prevent the engine from starting even if it's getting spark and fuel. This is a very common cause of no-start issues.
* Cam Position Sensor (CMP): Similar to the CKP, the CMP sensor tells the computer the position of the camshaft. An issue here can also lead to a no-start condition.
* Ignition Control Module (ICM): This module controls the spark delivery. While you say you're getting spark, a weak or intermittent signal from the ICM could be the problem. The spark might be insufficient to ignite the fuel air mixture reliably.
* Computer (PCM/ECM): The Powertrain Control Module (PCM) or Engine Control Module (ECM) is the brain of the engine. A faulty PCM can prevent the engine from starting by failing to send the correct signals to other components. This is less likely but possible.
* Fuel Pressure Regulator: Even though you're getting fuel, ensure the fuel pressure is correct. A faulty fuel pressure regulator might not maintain adequate pressure for proper combustion. A fuel pressure gauge test is needed here.
* Airflow Sensor/Mass Airflow Sensor (MAF): A faulty MAF sensor can cause the computer to send the wrong fuel/air mixture ratio, leading to a no-start.
* Low Compression: While less likely given you have spark and fuel, very low compression in the cylinders could prevent the engine from starting. A compression test is needed here.
Troubleshooting Steps:
1. Check for Spark Strength: While you say you have spark, ensure it's strong enough. A weak spark might not be sufficient to ignite the fuel-air mixture. Use a spark tester for verification.
2. Check Fuel Pressure: Use a fuel pressure gauge to verify fuel pressure is within the specifications for your engine.
3. Inspect the CKP and CMP Sensors: Check for damage, corrosion, or loose connections. Consider replacing them if they're suspect, as they're relatively inexpensive parts.
4. Check for Diagnostic Trouble Codes (DTCs): Use an OBD-I scanner (for a 1993 model) to retrieve any diagnostic trouble codes stored in the PCM. These codes will provide clues to the problem.
5. Check wiring harnesses: Look for damaged or corroded wiring, particularly to the sensors and ignition system components.
Important Note: Without diagnostic tools (OBD-I scanner, multimeter, fuel pressure gauge) pinpointing the exact cause can be difficult. Taking it to a mechanic experienced with older vehicles might be necessary for a definitive diagnosis. Trying to replace parts randomly can be costly and time-consuming.
